Single stranded dinucleotides consist of two nucleotides that are linked by a 3'-5' phosphodiester bond via the 3' hydroxyl group of one nucleotide and the 5' hydroxyl group of the other one, just a as bonding occurs in native RNA.
They are abbreviated as pNpN where N stands for any nucleotide and p indicates the phosphodiester bond and remaining 5' phosphate group, respectively. Thus a guanine nucleotide would be abbreviated pGpG.
